1. Field of the Invention
The present invention relates to a push button switch construction wherein one depression of the push button is effective to close one set of switch contacts and the succeeding depression of the push button is effective to close another set of contacts, the arrangement being such that continued successive plunger depressions to switch a blade from one set of contacts to the other.
2. Brief Description of the Prior Art
In recent years, the push-button type switches have enjoyed an ever growing degree of popularity. Push button switches have a variety of uses such as in appliances or in business machines and can be of the single pole, double throw or double pole, double throw variety, depending on its application. In addition, some push button switches are provided with an indicator such as a light which can be actuated either independently of the switch or dependent on the switch.
Most push button switches have a switch blade assembly connected to a circuit and movable between a normal position and an unstable position so that electricity is allowed to flow through one part of the circuit in one position and another part of the circuit in the other position. An actuator assembly is provided for moving the switch blade assembly from its normal position to its unstable position. One kind of actuator assembly uses a ratchet member and a pawl. The pawl is usually attached to the push button for movement therewith and is an engagement with the ratchet member so that every depression of the push button rotates the ratchet member a given increment. The ratchet member has a cam associated therewith in engagement with the switch blade assembly. Every time the ratchet member is moved a given increment, the cam forces the contact assembly from one position to another position.
The problems most commonly encountered with push button switches of this type are twofold. First there is the cost of manufacture and second, the level of performance. The level of performance is affected due to tease of the part of the switch blade assembly, and the fatigue of the pawl caused by repeated depressions of the push button. In addition, there can be problems of synchronizing two switch blade assemblies in a double pole, double throw switch.